So I'm working on a new song, and in the middle I've got this big synth solo. I can play well enough, but I feel like I'm not getting anything I like. I don't want the solo to sound composed, but I also don't want it to sound like I'm just blowing off riffs with no real direction or purpose.

In my humble opinion, the best way to write a solo is definitively not try to write it. I mean, when you want to focus on doing music, you loose inspiration. And, by the way, your brain is more clever that your fingers : imagine it before playing it.Cheers !

Even if you can't sing well, sing. Sing to yourself. Sing in the privacy of your home. But sing."Nachman of Breslov"

Generally, if I say this sentence, it means that I have a fragment of that solo already in my head (that's how I know that a solo belongs in there).

Then, out of simple cohabitation with the song, new ideas emerge. I treasure especially moments when I'm distracted, and hum along the song by chance... It was easier when I was in a band, because the cohabitation with the song, rehearsal after rehearsal, or even playing it live and seeing people's reaction, made the song develop more organically, and ideas flow quicker.

Another thought: on other occassions, I feel that that initial fragment that appeared by chance is clearly, for example, "the end of a crescendo"... "a surprise changing the pace after something very different"... something like that. With that 'blueprint' in mind, it's trial and error, trial and error, cool it down for a few days when your ear burns out and then more trial and error, keeping the cool stuff you find, rinse and repeat until you're satisfied with the construction.

I also use the other resources mentioned above: loop, start recording and let yourself go for half an hour, later listen again to everything and see what sticks out -just like public speakers or actors or frontmen or professional athletes do that, and they discover unexpected positive and negative spots-...

To add to the great advice, you can't go wrong if you start the solo with a quote from the main melody. Then take it somewhere new. End either with a big dramatic high note or alternatively tuck back into the song. You can hear this approach in just about every style of music, and it works equally well with a composed or an improvised solo.

If there is a 'big synth solo' I usually, along with looping mentioned above, 'downgrade' to a simple piano sound that I like, and improv on the piano. After finding leads I go back to the wanted sound. Sometimes I find the synth sounds themselves are distracting. At other times the synth can be played like an electric guitar and in that case the sound matters.

When faced with a similar challenge, I might start with something similar to the main melody, or I'll add passing notes to the chord progression or arpeggiate the chords. I may play that section over and over again, looking for new ideas, different ways to play it, different notes to change. Once I have something acceptable, since I do almost everything with MIDI, I might go in to my DAW editor, and adjust a note here another note there and keep doing that, letting the solo or any other part, evolve from where it started. Sometimes just changing or adding a single note, can lead to other ideas and before long you can have something very different from your starting point.

I play guitar in a trio so there is always temptation to solo away since I'm the only melodic instrument but sometimes I find a solo is not actually what is needed, if a song is rich enough with either vocals/lyrics or other musical ideas I'll write an instrumental bridge instead or put in a riff or maybe some chord melody that is relevant to the melody but not necessarily full of single note ideas. An important band member that is often forgotten or neglected is 'space'.

GMaq wrote: An important band member that is often forgotten or neglected is 'space'.

Another way of putting it is that sometimes you "play quiet": silence is your contribution to the whole. It's not about filling every available spot with notes, it's about being at the service of the song, isn't it?

GMaq wrote: An important band member that is often forgotten or neglected is 'space'.

Another way of putting it is that sometimes you "play quiet": silence is your contribution to the whole. It's not about filling every available spot with notes, it's about being at the service of the song, isn't it?